Just like with building construction, the foundation of road construction will dictate its integrity — the base of an asphalt paving project determines whether the pavement lasts for years to come. One way to know if a contractor is helping to ensure that integrity is if they perform soil stabilization before begin paving. It’s important to know why soil stabilization is important, what it entails, and the benefits the process offers when it is a part of asphalt pavement installation.
What is Soil Stabilization?
Drainage is one big consideration when it comes to asphalt paving. Water under the surface of pavement can lead to a range of problems, from small cracks to deep potholes, or worse. Grading for proper drainage will mitigate much of this risk, but stabilizing the soil adds another layer of protection.
Depending on the geography of the area, the soil may not be ideal in its current state to be a base for asphalt paving. In fact, this is often not the case, and the ground needs to be stabilized with an additive and compacted with precision. Moisture levels, road use, and environmental factors also need to be taken into account during soil stabilization.
What Does Soil Stabilization Entail?
There are several methods of social stabilization and a variety of additives can be used to complete the process. Soil samples are a good way to determine which approach to take, but soil stabilization is the most common by far for projects like parking lots and municipal roadways. After grading, the soil is pulverized to the proper depth and the agent is added to form a subgrade layer. This creates a chemical reaction that “primes” the surface for several additional layers.
Refer to the project specifications; this can be done in many ways, using a range of professional asphalt paving equipment and tools that your contractor has access to and experience using. A professional will also know if other additives need to be added to the agent to increase resiliency. The goal here is to alter the pH of the soil under the asphalt and use it as a tool to help control moisture. Too much, and pavement will swell and contract, and too little moisture leads to brittle, cracking pavement. Both reduce the longevity of asphalt.
What are the Benefits?
There are several ways that soil stabilization can be beneficial during an asphalt paving project.
- Plasticity reduction: Plasticity is an attribute of pavement that refers to its ability to “bounce back.” Reduced plasticity of soil means that it will allow the asphalt to change shape under duress, but eventually return to its undamaged state (or as close to it as possible).
- Moisture reduction: Adding a chemical agent to the soil can reduce moisture retention, which supplements proper grading when it comes to drainage. This is especially beneficial in rainy climates or roadways that may be regularly exposed to nearby elements like water sources.
- Swell reduction: Part of retaining less moisture means that the soil won’t increase in volume and swell (and subsequently shrink), which alters the surface and can damage vehicles and lead to damage that, over time, will require repair or possibly replacement.
- Improved stability: Creating stability with chemical additives and proper compaction keeps the soil under the asphalt from shifting over time. Uneven subsurfaces change the plane of the asphalt top surface and can encourage or exacerbate the damage.
Who Performs Soil Stabilization?
Because soil stabilization is such an integral part of a successful asphalt paving project, this is best left up to the professionals — work with your contractor to navigate this phase. From the early planning stages to completion, asphalt paving projects take a lot of work to get done right. The provider you choose needs to have more than just asphalt, equipment, and labor. They should also have well-maintained equipment (plus spare machines) and well-trained, safety-conscious work crews.
Having one source for multiple services can be one way to save without sacrificing quality. We have the project management and paving experience necessary to complete large, multifaceted jobs with ease. Turn to us when you need applications for parking lots, pathways, base layer preparations, streets, recreational areas, and more.
Our experienced project managers, schedulers, and asphalt paving specialists deliver a superior finished job with the least disruption to your business or municipality as possible. When you’re ready to start your next asphalt paving project, we’ll be there to help!